Creation
SNII, AGB stars, and luminous red novae inject new grain superparticles.
Dust physics for GADGET-4
CosmicGrain
An open-source extension for evolving dust as explicit superparticles in cosmological galaxy simulations. Individual grain populations carry their own dynamics, size, composition, and stellar origin while evolving through creation, transport, growth, collisions, and destruction.
Motivation
Why evolve the grains explicitly?
Grain creation, processing, and destruction occur in very different environments. By following those grains directly, CosmicGrain can ask not only how much dust a galaxy contains, but where that dust came from, how its size distribution changed, and where it ultimately survives.
The same evolving grain population can then be connected to galaxy-scale dust scaling relations, grain-size distributions, and extinction properties such as R(V).
On-the-fly evolution
The dust-grain lifecycle
A controlled physics ladder illustrates how the simulated dust distribution responds as the principal CosmicGrain processes are introduced.
Dynamics
Gravity and aerodynamic drag transport dust independently of the gas, with optional radiation pressure.
Growth & processing
Gas-phase accretion, coagulation, and shattering reshape the grain population.
Destruction
Thermal sputtering, supernova shocks, and astration remove grains from the population.
Tracked quantities
More than dust mass
Dust is represented as a dynamical population rather than a passive scalar attached to gas.
DynamicsPosition, velocity, drag, and transport
Grain physicsRadius, growth, collisions, and destruction
CompositionCarbonaceous and silicate populations
ProvenanceStellar source and subsequent processing
EnvironmentLocal gas conditions through the ISM and halo
ObservablesScaling relations, size distributions, and extinction
Open source